Police cadets worked with Ham’s safer neighbourhood team (SNT) to fine shops that sold them age-restricted goods.
With the help of trading standards, Ham’s SNT fined three shops and arrested a shop employee for an alleged immigration offence.
Officers discovered the male was found to be wanted and was suspected of being in the UK illegally.
PCSO Molnar from Ham SNT said: “This arrest may have not been made if it were not for the information given to police from a local resident about underage drinking and the sale of alcohol to minors.
“I immediately informed my team who dealt with the matter swiftly”
Police sergeant Paul Dowsett from Ham SNT said: “Regular test purchase operations run by the Police inform shop owners that we are dealing with these offences in real time.
“We would like to pass on our thanks to the resident that informed us of this matter and guided us to an arrest.”